生长抑素一级结构的电喷雾质谱分析

Determination of first-order structure of somatostatin by electrospray ionization mass spectrometry

目的 生长抑素的分子量及其一级结构的测定。方法 应用电喷雾质谱法 (ESI MS)测定了环肽药物生长抑素的分子量 ,用 2 巯基乙醇将生长抑素的双硫键还原 ,再用源内碰撞诱导解离技术进行测定 ,根据其典型碎片离子确证其氨基酸序列。结果 测得生长抑素准分子离子峰 [M +H]+m z 16 37 8,[M +Na]+m z 16 5 9 5及 [M +2Na -H]+m z 16 81 5 ,[M + 2H]2 +m z819 5及 [M +H +Na]2 +m z 830 3,表明生长抑素的分子量为 16 36 7,与理论值一致。将双硫键还原后 ,用CID技术进行测定 ,得到了一系列y和b系列的特征碎片离子 ,证实生长抑素还原产物的氨基酸序列为A G C K N F F W K T F T S C。结论 用ESI

Aim To determine the molecular weight and first order structure of somatostatin. Methods The molecular weight of somatostatin was determined by electrospray ionization mass spectrometry. Somatostatin was deoxidized by 2 mercaptoethanol. A series of typical fragment ions of deoxidized product were obtained by in source collision induced dissociation (CID). Results The m/z of quasi molecular ion [M+H] + of somatostatin was 1 637 8 and [M+Na] + was 1 659 5 . The m/z of double...